Several different types of circuits require the generation of multiple analog output voltages in accordance with digital input signals. In such circuits it has been customary to implement this function using a separate digital to analog converter for each required output voltage.
This approach is adequate when only a few analog voltages must be generated. However, certain types of circuits, such as charge to digital converters, may require generation of many such analog voltages. Even if integrated circuits are used to implement such circuits, the voltage generating function can occupy much space in a design.